Summary

A translocation of wild-bred and captive-bred Little Penguin Eudyptula minor fledglings was trialled to reinforce (augment) an urban population of this species in Sydney Harbour, Australia. Over three breeding seasons (2004/05 to 2006/07), a total of 44 wild-bred fledglings from nearby Lion Island and 19 captive-bred fledglings from local zoos were translocated to Store Beach, North Harbour, within Sydney Harbour. All translocated birds were implanted with a numbered microchip before release. During the same period, the North Harbour colony produced at least 327 fledglings, of which 113 were implanted with microchips prior to fledging. The North Harbour colony was monitored between 2005 and 2013 to identify any returning translocated or locally wild-bred birds. Three translocated wild-bred birds and 12 locally wild-bred birds are known to have returned to North Harbour, but no translocated captive-bred birds. One translocated wild-bred bird returned to Store Beach while the remaining two returned to adjacent headlands. The number of pairs of Little Penguin breeding on Store Beach, where threats are intensively managed, has increased from one in 2004 to nine in 2013. This study demonstrated that translocation of wild-bred fledglings is feasible. However, because of naturally low return rates, translocations of Little Penguins need to involve a large number of individuals, preferably taken from a sizeable donor colony, to be effective in reinforcing a threatened or declining population. The effectiveness of releasing captive-bred Little Penguins has yet to be demonstrated.